US 6,333,843 B2Granted

Method of starting an electromagnetic actuator operating a cylinder valve of a piston-type internal-combustion engine

AssigneeFEV Motorentechnik GmbH

InventorsChristian Boie, Lutz Kather, Günter Schmitz, Frank Van der Staay, Günter Rudolf Feyerl

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method for starting up an electromagnetic actuator operating an engine cylinder valve. The actuator has two spaced electromagnets, between which an armature, connected to the cylinder valve, is reciprocated against a restoring spring from a center position to lie against a magnet pole face. An ECU alternatingly supplies the electromagnets with a capturing current, the level of which is regulated as a function of the approach of the armature toward a pole face, as detected by a sensor assembly. A reference temperature is detected for the magnets, and, at a normal temperature, the armature starts oscillating due to the alternating energization of the electromagnets, and is brought into contact with a pole face. Or, at a low temperature level, one of the electromagnets is supplied with a high current pulse.

Claims11

Dependent claims

A method of starting an electromagnetic actuator for operating a cylinder valve of a piston-type internal-combustion engine, the actuator having

two spaced electromagnets having respective pole faces oriented toward one another;
one of the electromagnets being a valve-closing electromagnet and the other of the electromagnets being a valve-opening electromagnet;
a restoring spring;
an armature connected to the cylinder valve and being arranged for reciprocation between the electromagnets against the force of the restoring spring;
and
an ECU alternatingly supplying the electromagnets with a capturing current, the level of which being regulated as a function of the distance of the armature toward at least one pole face, the method comprising the following steps:
(a) detecting a temperature at least at one of the electromagnets;
(b) in case the temperature determined in step (a) is within a predetermined normal temperature range,
(1) beginning to oscillate the armature by alternatingly supplying current to the electromagnets at a resonant frequency of an oscillating system comprising the armature, the cylinder valve and the restoring spring;
and
(2) bringing the armature into contact with one of the pole faces;
and
(c) in case the temperature determined in step (a) is below the predetermined normal temperature range, supplying one of the electromagnets with a high current pulse.

10 more elements

Dependencies are inferred from the claim text.